All coinbase users that didn't pay taxes on gains after selling their BTC or trading alts are F*'d up.
FTFY.
Or do you have to pay taxes on a yearly base regardless of whether or not you've liquidated your assets in the US?
Good question, actually. Don't have an answer for you :| To my understanding, there is only a tax obligation upon any realized profit or loss, but what do I know.
I know that is the case in (at least some parts of) Europe and Canada.
I haven't checked the US in detail yet as most states have far too high capital gains taxes for my taste...
Would appreciate it if somebody could clarify this though, as I've been looking for a new place to move to in the near future and some parts of the US were actually on the list.